Phone area codes for Hamilton, ON

Hamilton sits at the western end of Lake Ontario and is historically known as Canada's Steel Capital. It now anchors a diverse economy spanning health care, education, and advanced manufacturing.

Dialling from and to Hamilton

Because Hamilton sits inside an overlay region with 4 overlapping area codes, callers must always dial 10 digits — even for calls between two phones on the same street. From outside Canada and the United States, dial your international access prefix, then +1, then the 10-digit number.

Mobile carriers in Hamilton typically issue numbers from whichever overlay code is currently being released by the NANP relief plan. As a result, two members of the same household frequently carry numbers from two different area codes — for example a long-time resident with an original-assignment number and a newer subscriber with an overlay number.

About Hamilton, Ontario

Hamilton is located in Ontario, Canada. Hamilton sits at the western end of Lake Ontario and is historically known as Canada's Steel Capital. It now anchors a diverse economy spanning health care, education, and advanced manufacturing. The city falls within the Eastern Time (EST/EDT, UTC-5/-4) time zone.

Numbers issued to subscribers in Hamilton can come from any of the area codes assigned to the surrounding numbering plan area: 905, 289, 365, 742. With number portability now standard across all Canadian carriers, the area code attached to a Hamilton number tells you only where that number was first issued — not who currently carries it or where the device is physically located.

If you are trying to identify a recent call from 905 or 289 or 365 or 742, the caller is most likely either based in Hamilton or another community within the same NPA, has previously held a number issued in this area, or — in the case of telemarketing and scam calls — is spoofing a local prefix to increase the chance you pick up.